feat: simple signals implementation

packages/signals/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "dioxus-signals"
+version = "0.0.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+dioxus-core = { path = "../core" }
+slab = "0.4.7"